The present invention relates to fasteners and more specifically to ratcheting fasteners.
It is common practice to use an externally threaded shaft, bolt, or tube and a corresponding internally threaded nut for securing joints, individual pieces, and through-wall sockets. Generally, either the shaft or the nut is rotated until the threads of the mating components are secured. This method is susceptible to several problems.
Firstly, mating threaded fasteners such as bolts and nuts are prone to loosening. Through vibration, thermal cycling, or other environmental conditions, the mating threaded elements move relative to each other, loosening the joint. When the joint is no longer clamped or secured, the threaded fastener loses its functionality.
Secondly, helical threads require the fastener system (i.e. shaft or nut or both) to be rotated relative to the mating pieces. Based on the amount of thread, this practice can be time consuming, leading to inefficiencies in the installation process.
Thirdly, helical thread fasteners require friction with a mating surface to prevent loosening and loss of functionality. As the fastener system is rotated, the nut moves axially along the external threads. Generally, the nut and head of the shaft apply the axial clamp force by contacting the surface of the mating objects. Significant torque is often needed to load the threads and retain the necessary clamping force. Friction is not only created in the threads but also on the mating surfaces. The friction created by this action can damage the mating surfaces or even the fastener itself. If any mating surface or the fastener is coated, this damage can remove the coating. Since coatings are often used to protect surfaces from environmental corrosion, damage of the coating can shorten product life.